If you're using the solution below and the command prompt says something like "The system could not find the specified path" then you have to do step 4 differently if your System 32 and SysWOW64 are not together. I wouldn't move them together so instead type "cd C:/Windows/SysWOW64" without quotes and continue on. A prompt will say it has succeeded for both steps if done correctly. Hope I helped.

commented over a year ago:

If you are using the 64-bit
version of any one of these windows Vista, 7, and 8... you have to put dx7vb.dll and
dx8vb.dll in the SysWOW64
directory... DO LYK THIS -
1. copy the dx7vb and dx8vb dlls to
C:WindowsSysWOW64
2. Start COMMAND PROMPT as an administrator
3. type "cd... "
without quotes and hit enter
4. then type "cd SysWOW64" without quotes and hit enter
5. type "regsvr32 dx7vb.dll" without quotes and hit enter
6. then type "regsvr32 dx8vb.dll" without quotes and hit enter ALL DONE ;-)
NOW START SAAC > THENT SET ALL CONTROLS (set all joystick controls by maching them in gta sa game contoller settings)> SET VIRATION/RUMBLE... AND ENJOY

Thanks to the three folks who posted further instructions for running this mod on newer versions of Windows (I'm running Windows 8).
Using SAAC I've got the right analog stick working, which was my main issue before, but now the main directional control on the left analog stick is all wonky! I think it's changed it from the classic "camera-relative" direction to "character-relative." Now I can't even complete one of the earliest missions that requires hopping a fence because it's so hard to perfectly face the darn thing. I tried unbinding the main directional controls on SAAC since they were working fine before (using a PS3 controller with Motioninjoy) and that just made all movement impossible (unless I tried completing the game by hopping around and punching the air). Any help on getting back to the normal way of movement while still being able to use the right analog joystick?

Take note of this: If you are using the 64-bit versions of Vista, 7, and 8, dx7vb.dll and dx8vb.dll has to be put in the SysWOW64 directory, not System32.
Here's how I did it:
copy the dx7vb and dx8vb dlls to C:WindowsSysWOW64,
Run cmd.exe as an admin (you don't have to play with the UAC or restart or anything like that),
type "cd... " without quotes,
then type in "cd SysWOW64", again without quotes,
type in "regsvr32 dx7vb.dll", hit enter,
then type in "regsvr32 dx8vb.dll", hit enter.
and like I said, without quotes. if done right, SAAC should start up.

To get this mod to work with windows 7 "FOR SURE", follow these easy instructions...
1. Go to google search for these 2 files "dx8vb.dll" and "dx7vb.dll". Download them anywhere. Move them into your system32 folder(C:WINDOWSSystem32).
2. Go into the User Preferences in the Control Panel and turn off User Account Control. After restart your computer.
3. Go to "start", "all programs", "run", or just type "run" in the search bar. A window should open. Type "CMD" Another window should open after you clicked enter the window should be named, "C:Windowssystem32cmd.exe". Type in "regsvr32 dx8vb.dll" make sure you put the space in between. Push Enter It should say ok or Succsessfull. Then type in "regsvr32 dx7vb.dll" dont forget the space. Push Enter It should say Ok or Successfull Try to open SAAC.

Uhm I did everything exactly how you have instructed and I have Windows 7 and it still doesn't even work. I have even taken the time to copy/paste everything which it will not let me register the .dlls of course.

NICE!! I love this application. Took me awhile to configure it. The only reason I spent 30 minutes installing .dll and configuring it was for the RUMBLE and it works! Thank You very much Did the game always come with rumble or is this a hack? if it is it would be awesome if it was a cleo